Mount Wilson Observatory is a historic astronomical research facility located in the San Gabriel Mountains of California. Established in 1904, it played a crucial role in advancing our understanding of the universe, particularly through its large telescopes, including the 60-inch and 100-inch reflectors. The observatory has contributed significantly to various fields of astronomy, including the study of nebulae and galaxies. It was here that astronomer Edwin Hubble discovered the expansion of the universe, leading to the formulation of Hubble's Law. Today, the observatory continues to be a center for research and public outreach in astronomy.